Ultra-compact relay with high creepage distance

Abstract

This disclosure provides a microminiature relay with a high creepage distance, comprising a base portion (2) and a movable contact spring / armature combination (3). The base portion (2) comprises a coil (26), an iron core (21), a fixed contact spring, a coil terminal (22), and a first plastic body (23) that integrates the coil (26), the iron core (21), the fixed contact spring, and the coil terminal (22) into a single unit by injection molding. In the base portion (2), the fixed contact spring injection-molded into the first plastic body (23) includes only a normally-open fixed contact spring piece (24) located at a position corresponding to the other end of the coil axis of the first plastic body (23) and a welding base (25) with a welding lug structure (311) for supporting at least the movable contact spring / armature combination (3) at a position corresponding to the middle of the coil axis, but no normally-closed fixed contact spring. The present disclosure can effectively improve the creepage distance between the coil (26) and the contacts without increasing the volume of the relay, thereby meeting the increasingly higher creepage distance requirements for the input and output of relays in fields such as new energy and automotive applications.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims priority to a Chinese patent application bearing application number 202011609586.3, filed on December 30, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the field of relay technology, and more particularly to a miniature relay having high creepage distance. [Background technology]

[0003] In a conventional micro relay, a cut fixed contact spring piece is generally connected to a coil, a base, etc. by injection molding, and the lead terminals of the fixed contact spring piece and the lead terminals of the coil terminal are formed by folding an injection-molded cut sheet body, and the lead terminals of such a micro relay are generally distributed along both sides of the coil axis. FIG. 1 is a three-dimensional structure schematic diagram of a conventional micro relay (not including a housing). FIG. 2 is a structural schematic diagram of a combination of a movable contact spring and an armature of a conventional micro relay. FIG. 3 is a structural schematic diagram of a base part of a conventional micro relay. As shown in FIG. 1, FIG. 2 and FIG. 3, such a conventional micro relay is formed by assembling a coil, an iron core 101, a fixed contact spring and a coil terminal 102 by injection molding to form a base part 100 including a plastic body 109, where the fixed contact spring includes two normally open fixed contact spring pieces 103, two normally closed fixed contact spring pieces 104 and two common end spring pieces 105. Normally open fixed contact spring piece 103, normally closed fixed contact spring piece 104 and common end spring piece 105 are provided with normally open fixed contact spring lead-out terminal 1031, normally closed fixed contact spring lead-out terminal 1041 and common end lead-out terminal 1051, respectively, which are exposed to the outside of plastic body 109. Normally open fixed contact 1032 and normally closed fixed contact 1042 are further connected to the parts of normally open fixed contact spring piece 103 and normally closed fixed contact spring piece 104 exposed at the upper end of the plastic body, respectively. The movable contact spring and armature combination 106 of this micro-miniature relay is formed by injection molding two sets of movable contact spring pieces 107 and armatures 108 into an integrated structure including a plastic part 110, and both ends of each set of movable contact spring pieces 107 respectively form a normally open side 1071 and a normally closed side 1072 exposed to the outside of the plastic part 110, and a welded lug structure 1073 exposed to the outside of the plastic part 110 is provided in the middle, and a normally open movable contact and a normally closed movable contact are attached to the normally open side 1071 and the normally closed side 1072 of the movable contact spring piece 107, respectively. When attaching the movable contact spring and armature combination 106 to the base portion 100, the welded lug structure 1073 of the movable contact spring and armature combination 106 and the welded base of the common end spring piece 105 of the base portion 100 are fixed together by welding, thereby causing the movable contact spring and armature combination 106 to have a seesaw structure.In the base part 100, the lead-out terminal 1021 of the coil terminal 102 is located at one end of the plastic body 109, the normally closed fixed contact spring lead-out terminal 1041, the common end lead-out terminal 1051 and the normally open fixed contact spring lead-out terminal 1031 are distributed in order from one end of the plastic body 109 to the other end of the plastic body 109, and the normally open fixed contact spring lead-out terminal 1031 is located at the other end of the plastic body 109. As shown in Fig. 3, such a prior art ultra-miniature relay has a small product volume and a compact overall structure, which causes a drawback that the creepage distance M between the coil terminal 102 and the fixed contact spring (normally closed fixed contact spring piece 104) and the creepage distance N between the coil terminal 102 and the fixed contact (normally closed fixed contact 1042) are both short, and cannot meet the increasingly higher safety requirements (i.e., high creepage distances) for the input and output (i.e., between the coil and the contacts) of the relay in the fields of new energy, vehicle mounting, etc. Summary of the Invention

[0004] The objective of the present disclosure is to overcome the shortcomings of the prior art and provide an ultra-miniature relay with a high creepage distance, and by improving the structure, the creepage distance between the coil and the contacts can be effectively increased without increasing the volume of the relay, thereby meeting the increasingly higher safety requirements for the input and output of the relay in fields such as new energy and automotive.

[0005] The technical solutions used in the present disclosure to solve the technical problem are as follows: a micro-miniature relay with a high creepage distance, comprising a base part and a combination of a movable contact spring and an armature; the base part comprises a coil, an iron core, a fixed contact spring, a coil terminal and a first plastic body, the first plastic body is formed into an integral part by an injection molding method, and the first plastic body completely covers the coil; the pole faces of both ends of the iron core respectively protrude from within the first plastic body to the upper end of the first plastic body and are located at both ends of the first plastic body, and the part of the coil terminal exposed from the first plastic body is located at one end of the first plastic body; the combination of the movable contact spring and the armature comprises two sets of movable contact spring pieces, an armature and a second plastic body, the second plastic body is formed into an integral part by an injection molding method, the contact spring piece and the armature are integrated into an integral member; a welding lug structure is provided at the intermediate position of the combination of the movable contact spring and the armature, the combination of the movable contact spring and the armature is attached to the intermediate position of the top end of the base part by the welding lug structure, and both ends of the armature exposed from the second plastic body correspond to and cooperate with the pole surfaces of both ends of the iron core; the fixed contact spring injection molded in the first plastic body only includes a normally open fixed contact spring piece and a welding base, and does not include a normally closed fixed contact spring piece, the normally open fixed contact spring piece is located at the other end of the first plastic body, the welding base is located corresponding to the intermediate position of the first plastic body and is used to support at least the welding lug structure of the combination of the movable contact spring and the armature, and the normally closed fixed contact spring piece is eliminated to improve the creepage distance outside the first plastic body between the coil terminal and the fixed contact spring.

[0006] The axis of the coil is horizontal and the core is U-shaped.

[0007] A welding lug structure is provided on each side of the intermediate position of the combination of the movable contact spring and the armature, and the two welding lug structures are respectively integrally provided with a corresponding set of movable contact spring pieces and exposed outside the second plastic body; the movable contact spring pieces have an asymmetric structure with respect to the welding lug structures, and one side of the movable contact spring pieces corresponding to the normally open fixed contact spring pieces is provided with a normally open side exposed outside the second plastic body, and a normally open movable contact is attached to the normally open side of the movable contact spring pieces; the other side corresponding to the normally open side of the movable contact spring pieces is completely covered within the second plastic body.

[0008] The horizontal cross section of the first plastic body has a rectangular or nearly rectangular shape, and a first groove is provided in a side wall corresponding to the long side of the rectangle of the first plastic body, corresponding to the surface path between the portion of the coil terminal exposed from the first plastic body and the welding table exposed from the first plastic body, and the first groove is used to increase the surface distance between the portion of the coil terminal exposed from the first plastic body and the welding table.

[0009] The horizontal cross section of the first plastic body has a rectangular or nearly rectangular shape; a first barrier is further provided at a top end adjacent to one end of the first plastic body on a side wall corresponding to the long side of the rectangle of the first plastic body, and protrudes upward, so that a creeping path from a portion of the coil terminal exposed from the first plastic body through the iron core to the normally open end contact creeps along the side wall corresponding to the short side of the rectangle of the first plastic body.

[0010] A second groove is provided on the side wall corresponding to the short side of the rectangle of the first plastic body in correspondence with the surface path between the portion of the coil terminal exposed from the first plastic body and one end of the iron core, and the second groove is used to increase the surface distance from the portion of the coil terminal exposed from the first plastic body, through the iron core, to the normally open end contact.

[0011] A second barrier is further provided on the upper end of the first plastic body corresponding to the creepage path between the other end of the core and the normally open end contact, and the second barrier is used to further increase the creepage distance from the portion of the coil terminal exposed from the first plastic body, through the core, to the normally open end contact.

[0012] The combination of the movable contact spring and the armature further includes a permanent magnet, the permanent magnet being distributed along the length of the armature and stacked with the armature, and the permanent magnet being offset toward the other end of the first plastic body. The movable contact spring piece further has a common end lead-out terminal exposed from the first plastic body on the welding table, facing downward, and the common end lead-out terminal is offset toward the other end of the first plastic body.

[0013] The two sets of movable contact spring pieces are further electrically connected between the other sides corresponding to the normally open side by a connecting sheet, and the connecting sheet is completely covered by the second plastic body; the connecting sheet is integrally connected to the two sets of movable contact spring pieces by an integral molding method, or the connecting sheet is a separate part, and both ends of the connecting sheet are abutted or welded to the two sets of movable contact spring pieces respectively.

[0014] The connecting sheet is adjacent to the end position of the corresponding end of the second plastic body, thereby providing sufficient arrangement space for the permanent magnet.

[0015] Compared with the prior art, the beneficial effects of the present disclosure are as follows:

[0016] 1. In the present disclosure, in the base part, the fixed contact spring injection-molded in the first plastic body only includes a normally open fixed contact spring piece and a welding base, and does not include a normally closed fixed contact spring piece, the normally open fixed contact spring piece is located at a position corresponding to the other end of the coil axis of the first plastic body, the welding base is located at a position corresponding to the middle position of the coil axis, and is used to support at least the welding lug structure of the combination of the movable contact spring and the armature. Such a structure in the present disclosure can improve the creepage distance between the coil terminal and the fixed contact spring by removing the normally closed fixed contact spring piece in the base part, thereby effectively improving the creepage distance between the coil and the contact without increasing the volume of the relay, thereby meeting the increasingly higher safety requirements for the input and output of the relay in the fields of new energy, automotive, etc.

[0017] 2. In the present disclosure, a first groove is provided in the first plastic body corresponding to the creepage path between the coil terminals of the input and output of the relay (i.e., between the coil and the contacts) and the welding base, thereby further improving the creepage distance between the coil and the contacts.

[0018] 3. The present disclosure provides that in the first plastic body, a second groove and a second barrier are further provided in the creepage path between the normally open end contacts through the iron core corresponding to the coil terminals of the input and output of the relay (i.e., between the coil and the contacts), and the first barrier is used to make the creepage path creep from the side wall corresponding to the long side of the rectangle of the first plastic body along the side wall corresponding to the short side of the rectangle of the first plastic body, thereby further increasing the creepage distance between the coil and the contacts.

[0019] 4. In the present disclosure, only a welding table is provided at a position corresponding to the common end of the first plastic body to support the welding lug structure of the combination of the movable contact spring and the armature, no lead-out terminal is provided, and the other side of the two sets of movable contact springs corresponding to the normally open side is further connected together by a connecting sheet. Such a structure in the present disclosure electrically connects the two sets of movable contact spring pieces by the connecting sheet, realizing a series connection of the normally open end contacts, and the contact gap is twice that of the relay in the prior art, which can effectively improve the contact gap, the withstand voltage of the contacts and the cutting ability of the product, thus satisfying the withstand voltage of the contact gap and the distance of the contact gap cutting, without the need for external series connection.

[0020] 5. In the present disclosure, the permanent magnets are distributed along the longitudinal direction of the armature and stacked with the armature, and the permanent magnets are offset toward the other end of the first plastic body. This structure of the present disclosure uses an unbalanced double magnetic circuit structure to provide a larger deflection force at the normally open end, and avoids the occurrence of the phenomenon that the normally closed contact pressure of the seesaw type relay is not sufficient to operate the relay, and ensures the relay to operate reliably.

[0021] The present disclosure will be described in more detail below with reference to the drawings and examples; however, the microminiature relay with high creepage distance of the present disclosure is not limited to the examples. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of the three-dimensional structure of a prior art microminiature relay (not including the housing). [Diagram 2] FIG. 2 is a structural schematic diagram of a combination of a movable contact spring and an armature of a prior art microminiature relay. [Diagram 3] FIG. 3 is a schematic diagram showing the three-dimensional structure of a base portion of a conventional microminiature relay. [Figure 4] FIG. 4 is a schematic diagram of the three-dimensional structure of the first embodiment of the present disclosure (not including the housing). [Diagram 5]FIG. 5 is a left side view (not including the housing) of the first embodiment of the present disclosure. [Figure 6] FIG. 6 is a right side view (not including the housing) of the first embodiment of the present disclosure. [Figure 7] FIG. 7 is a structural cross-sectional view (including the housing) of the first embodiment of the present disclosure. [Figure 8] FIG. 8 is a schematic diagram of the three-dimensional structure of the base portion of the first embodiment of the present disclosure. [Figure 9] FIG. 9 is a cross-sectional view of a base portion of the first embodiment of the present disclosure. [Figure 10] FIG. 10 is a schematic diagram of the three-dimensional structure of a combination of a movable contact spring and an armature according to the first embodiment of the present disclosure. [Figure 11] FIG. 11 is a bottom view of a combination of a movable contact spring and an armature according to the first embodiment of the present disclosure. [Figure 12] FIG. 12 is a bottom view of the movable contact spring and armature combination (with the second plastic body removed) of the first embodiment of the present disclosure. [Figure 13] FIG. 13 is a schematic diagram of the three-dimensional structure of the combination of the movable contact spring and the armature (with the second plastic body removed) of the first embodiment of the present disclosure. [Figure 14] FIG. 14 is a schematic diagram of a magnetic circuit structure according to the first embodiment of the present disclosure. [Figure 15] FIG. 15 is a structural cross-sectional view of the first embodiment of the present disclosure (not including the housing, and with the normally closed end of the magnetic circuit closed). [Figure 16] FIG. 16 is a structural cross-sectional view of the first embodiment of the present disclosure (not including the housing, and with the normally open end of the magnetic circuit closed). [Figure 17] FIG. 17 is a distribution schematic diagram of the coil terminals and the fixed contact springs according to the first embodiment of the present disclosure. [Figure 18] FIG. 18 is a schematic diagram of an application in which the coil terminal, the fixed contact spring, and the movable contact spring piece of the first embodiment of the present disclosure are engaged with each other. [Figure 19] FIG. 19 is a schematic diagram of a three-dimensional structure of the second embodiment of the present disclosure (not including the housing). [Figure 20]FIG. 20 is a schematic diagram of the three-dimensional structure of the base portion of the second embodiment of the present disclosure. [Figure 21] FIG. 21 is a structural schematic diagram of a combination of a movable contact spring and an armature (with the second plastic body removed) of the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Example 1 As shown in Figures 4 to 18, the micro relay with high creepage distance disclosed herein includes a housing 1, a base part 2, and a combination of a movable contact spring and an armature 3. The base part 2 includes a coil 26, an iron core 21, a fixed contact spring, a coil terminal 22, and a first plastic body 23. The first plastic body 23 is formed by integrating the coil 26, the iron core 21, the fixed contact spring, and the coil terminal 22 into a single member by injection molding, and the first plastic body 23 completely covers the coil 26. The coil 26 includes a bobbin and an enameled wire. In this embodiment, the axis of the coil 26 is horizontally disposed, and the pole faces 211 at both ends of the iron core 21 protrude from the first plastic body 23 and are disposed on the top of the first plastic body 23. and are located at both ends of the first plastic body 23, there are two coil terminals 22, and the two coil terminals 22 are located at one end of the first plastic body 23, i.e., the part of the coil terminal 22 exposed from the first plastic body is located at one end of the first plastic body, and the part of the coil terminal 22 exposed from the first plastic body includes a coil lead-out terminal 221, which is located approximately at the corner position of one end of the first plastic body 23, and the first plastic body 23 includes a seat. The movable contact spring and armature combination 3 includes two sets of movable contact spring pieces 31, an armature 32 and a second plastic body 33, and the second plastic body 33 integrates the two sets of movable contact spring pieces 31 and the armature 32 into an integral member by injection molding, where, along the coil axial direction, the armature 32 is in the middle, and the two sets of movable contact spring pieces 31 are on both sides of the armature 32. A welding lug structure 311 is provided on both sides of the intermediate position of the combination 3 of the movable contact spring and armature, the welding lug structure 311 of the combination 3 of the movable contact spring and armature is attached to the intermediate position of the top end of the base portion 2, and both ends of the armature 32 exposed from the second plastic body 33 in the combination 3 of the movable contact spring and armature correspond to and cooperate with the pole faces 211 at both ends of the iron core 21.In the base part 2, the fixed contact spring injection-molded in the first plastic body 23 only includes the normally-open fixed contact spring piece 24 and the welding base 25, and does not include the normally-closed fixed contact spring piece, the normally-open fixed contact spring piece 24 is located at the other end of the first plastic body 23, the welding base 25 corresponds to the center of the first plastic body 23, and is used to support at least the welding lug structure 311 of the combination 3 of the movable contact spring and armature, and improves the creepage distance outside the first plastic body between the coil terminal and the fixed contact spring by eliminating the normally-closed fixed contact spring piece. In this embodiment, the iron core is U-shaped.

[0024] In this embodiment, the welded lug structure 311 is integral with the movable contact spring piece 31 and is exposed to the outside of the second plastic body 33. The movable contact spring piece 31 has an asymmetric structure with respect to the welded lug structure, in which one side of the movable contact spring piece 31 corresponding to the normally open fixed contact spring is provided with a normally open side 312 exposed to the outside of the second plastic body, a normally open movable contact 313 is attached to the normally open side 312 of the movable contact spring, and the other side of the movable contact spring piece 31 corresponding to the normally open side is completely covered within the second plastic body 33.

[0025] The present disclosure provides a normally open seesaw relay by removing the normally closed fixed contact spring and the normally closed side of the movable contact spring of the seesaw relay.

[0026] In this embodiment, the horizontal cross section of the first plastic body 23 has a rectangular or nearly rectangular shape, and a first groove 232 is provided in the side wall corresponding to the long side of the rectangle in the first plastic body 23, i.e., the side wall 231 parallel to the coil axis, at a surface distance corresponding to between the portion of the coil terminal 22 exposed from the first plastic body and the welding table 25 exposed from the first plastic body 23, and the first groove 232 is used to increase the surface distance between the portion of the coil terminal 22 exposed from the first plastic body and the welding table 5.

[0027] In this embodiment, a first barrier 235 is further provided at the top end of the side wall 231 corresponding to the long side of the rectangle of the first plastic body 23, adjacent to one end of the first plastic body 23, and protrudes upward, so that the creeping path from the part of the coil terminal 22 exposed from the first plastic body, through the iron core 21, to the normally open end contact creeps along the side wall 233 corresponding to the short side of the rectangle of the first plastic body 23.

[0028] In this embodiment, in the first plastic body 23, a side wall corresponding to the short side of the rectangle of the first plastic body 23, i.e., a side wall 233 perpendicular to the coil axis, is provided with a second groove 234 of a surface path corresponding to between the part of the coil terminal 22 exposed from the first plastic body and one end of the iron core 21, and the second groove 234 is used to increase the surface distance from the part of the coil terminal 22 exposed from the first plastic body through the iron core to the normally open end contact. In this embodiment, a second barrier 236 is further provided at the upper end of the first plastic body 23 in the corresponding creepage path between the other end of the iron core 21 and the normally open end contact, and the second barrier 236 is used to further increase the creepage distance from the part of the coil terminal 22 exposed from the first plastic body through the iron core to the normally open end contact.

[0029] In this embodiment, the movable contact spring and armature combination 3 further includes a permanent magnet 34, which is distributed along the longitudinal direction of the armature, i.e., the axial direction of the coil, and is stacked with the armature 32, and the permanent magnet 34 is offset toward this side direction of the other end of the first plastic body, and is actually offset toward this side direction of the normally open side 312 of the movable contact spring piece 31. That is, the midline of the permanent magnet 34 is offset relative to the midline of the armature 32, and is offset to the normally open end of the magnetic circuit.

[0030] In this embodiment, the other sides of the two sets of movable contact spring pieces 31 corresponding to the normally open sides are further electrically connected by a connecting sheet 35, and the connecting sheet 35 is completely covered in the second plastic body 33. The connecting sheet may be integrally molded between the other sides of the two sets of movable contact spring pieces 31 corresponding to the normally open sides, and the two sets of movable contact spring pieces 31 are the same part and are approximately U-shaped. The connecting sheet may be a separate part, and both ends of the connecting sheet are fixed to the other sides of the two sets of movable contact spring pieces 31 corresponding to the normally open sides by welding, or both ends of the connecting sheet are hung on the other sides of the two sets of movable contact spring pieces 31 corresponding to the normally open sides and injection molded, thereby realizing that both ends of the connecting sheet are in close contact with the two sets of movable contact spring pieces 31 respectively.

[0031] In this embodiment, the connecting sheet 35 is adjacent to the end position of the corresponding end of the second plastic body 33, thereby providing sufficient arrangement space for the permanent magnet 34.

[0032] The relays in this embodiment are a pair of normally open relays.

[0033] In the micro relay with high creepage distance disclosed herein, the fixed contact spring injection-molded in the first plastic body 23 in the base part 2 only includes the normally open fixed contact spring piece 24 and the welding base 25, does not include the normally closed fixed contact spring piece, the normally open fixed contact spring piece 24 is located at the other end of the first plastic body corresponding to the coil axis, the welding base 25 corresponds to the center position of the coil axis, and is used to support the welding lug structure of at least the combination of the movable contact spring and the armature. Such a structure disclosed herein can improve the creepage distance between the coil terminal 22 and the fixed contact spring by removing the normally closed fixed contact spring piece in the base part 2, and realizes the effective improvement of the creepage distance between the coil and the contacts without increasing the volume of the relay, thereby meeting the increasingly higher insulation requirements for the input and output of the relay in the fields of new energy, automotive, etc.

[0034] In the micro relay with high creepage distance of the present disclosure, a first groove 232 is provided in the creepage path corresponding to the coil terminals of the input and output (i.e., between the coil and the contacts) of the relay and the welding base in the first plastic body 23, so that the creepage distance between the coil and the contacts can be further improved. In the present disclosure, a second groove 234 and a second barrier 236 are further provided in the creepage path between the iron core 21 and the normally open end contacts in the first plastic body 23, corresponding to the coil terminals of the input and output (i.e., between the coil and the contacts) of the relay, and a first barrier 235 is used to make the creepage path creep from the side wall 231 corresponding to the long side of the rectangle of the first plastic body along the side wall 233 corresponding to the short side of the rectangle of the first plastic body, so that the creepage distance between the coil and the contacts can be further improved. As shown in Figures 5, 6 and 8, there are two creepage distances between the coil terminal and the normally-open end contacts. One creepage distance is from the part of the coil terminal 22 exposed from the first plastic body to the welding table 25 (because the welding table is directly connected to the normally-open end contacts), and the creepage distance S of this creepage distance is from the part of the coil terminal 22 exposed from the first plastic body to the welding table 25. The other creepage distance is from the part of the coil terminal 22 exposed from the first plastic body to the normally-open end contacts, via the iron core, and the creepage distance of this creepage path is the sum of the distance D1 from the part of the coil terminal 22 exposed from the first plastic body to one end of the iron core 21 and the distance D2 from the other end of the iron core 21 to the normally-open end contacts. Of the two creepage distances, the shorter creepage distance is the creepage distance between the coil and the contacts of the relay.

[0035] In the micro relay with a high creepage distance disclosed in the present invention, the permanent magnet 34 is distributed along the longitudinal direction of the armature, i.e., the axial direction of the coil, and is laminated with the armature 32, and the permanent magnet 34 is offset toward one side of the other end of the first plastic body, i.e., toward one side of the normally open side of the movable contact spring piece. As shown in Figures 14 to 16, this structure disclosed in the present invention uses an unbalanced double magnetic circuit structure to provide a larger deflection force at the normally open end, and can avoid the occurrence of the phenomenon that the relay is difficult to operate or difficult to operate due to the lack of normally closed contact pressure in a seesaw type relay, and can ensure the relay to operate. When the relay is in the initial state as shown in Figure 15, the magnetic force of the permanent magnet and the elastic reaction force of the movable contact spring are in the same direction, and the armature restoring force = magnetic force of the permanent magnet + elastic reaction force of the movable contact spring. In the conventional structure, contact pressure occurs due to overrun of the normally closed contact, that is, armature restoring force = magnetic force of permanent magnet + elastic reaction force of movable contact spring - normally closed contact pressure. As shown in Figure 16, when the relay is in the operating state (normally open contact is closed), the relay is subjected to the coil attractive force, and the magnetic force of the permanent magnet and the elastic reaction force of the movable contact spring are in the opposite directions, and at this time the armature restoring force = electromagnetic attractive force of coil + magnetic force of permanent magnet - reaction force of movable contact spring - contact pressure.

[0036] The micro relay with high creepage distance disclosed herein only has a welding base 25 with a welded lug structure for supporting the combination of the movable contact spring and the armature at a position corresponding to the common end of the first plastic body, and no lead-out terminal is provided, and the other side of the two sets of movable contact spring pieces 31 corresponding to the normally open side is connected together by a connecting sheet 35, and the connecting sheet 35 is placed close to the end position of the corresponding end of the second plastic body 33, thereby providing sufficient arrangement space for the permanent magnet. As shown in Fig. 18, such a structure disclosed herein electrically connects the two sets of movable contact spring pieces 31 through the connecting sheet 35, realizing a series connection of the normally open end contacts, and the contact gap is twice that of the relay of the prior art, which can effectively improve the contact gap, the withstand voltage of the contacts and the cutting ability of the product, and thus can meet the withstand voltage of the contact gap and the distance of the contact gap cutting without requiring an external series connection.

[0037] Example 2 19 to 21, the micro relay with a high creepage distance disclosed herein is different from the first embodiment in the following points. In the fixed contact spring, the welding base 25 is further provided with a common end lead terminal 251 exposed from the first plastic body 23 facing downward, and the common end lead terminal 251 is offset toward the other end of the first plastic body 23. As a result, the relay of this embodiment is a two-set normally open relay.

[0038] The above are only preferred embodiments of the present disclosure, and do not limit the present disclosure in any manner. The present disclosure has been disclosed above by preferred embodiments, but does not limit the present disclosure. Those skilled in the art can make many possible changes and modifications to the technical solutions of the present disclosure using the technical content disclosed above without departing from the scope of the technical solutions of the present disclosure, or can modify them into equivalent equivalent embodiments. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the essence of the technology of the present disclosure without departing from the content of the technical solutions of the present disclosure should all be included in the protection scope of the technical solutions of the present disclosure.

Claims

1. A microminiature relay with a high creepage distance, comprising a base portion and a combination of a movable contact spring and an armature, the base portion comprising a coil, an iron core, a fixed contact spring, a coil terminal and a first plastic body, the first plastic body being formed by injection molding to integrate the coil, the iron core, the fixed contact spring and the coil terminal into a single piece, the first plastic body completely covering the coil, the pole faces at both ends of the iron core protruding from the first plastic body respectively and extending to an upper end of the first plastic body, and being located at both ends of the first plastic body respectively, the coil terminals being exposed from the first plastic body are formed in the first plastic body and the pole faces at both ends of the first plastic body are formed in the first plastic body and extend to an upper end of the first plastic body, the pole faces at both ends of the first plastic body protruding from the first plastic body respectively and extending ... a movable contact spring and armature assembly including two sets of movable contact spring pieces, an armature and a second plastic body, the second plastic body being formed by injection molding to integrate the two sets of movable contact spring pieces and the armature into a one-piece member, a welding lug structure being provided at a middle position of the movable contact spring and armature assembly, the movable contact spring and armature assembly being attached to a middle position of a top end of the base portion by the welding lug structure, and both ends of the armature exposed from the second plastic body being engaged with corresponding pole faces of both ends of the iron core, The fixed contact spring injection molded in the first plastic body only includes a normally-open fixed contact spring piece and a welding base, and does not include a normally-closed fixed contact spring piece, the normally-open fixed contact spring piece is disposed at the other end of the first plastic body, the welding base is disposed corresponding to the middle position of the first plastic body, and is used to at least support the welding lug structure of the combination of the movable contact spring and the armature, and improves the creepage distance outside the first plastic body between the coil terminal and the fixed contact spring by removing the normally-closed fixed contact spring piece. A miniature relay having a high creepage distance.

2. The axis of the coil is horizontal, and the core is U-shaped.

2. A microminiature relay having a high creepage distance according to claim 1.

3. The welding lug structures are provided on both sides of the intermediate position of the combination of the movable contact spring and the armature, and the two welding lug structures are respectively integrally provided with a corresponding pair of the movable contact spring pieces and exposed outside the second plastic body, the movable contact spring pieces have an asymmetric structure with respect to the welding lug structures, one side of the movable contact spring piece corresponding to the normally open fixed contact spring piece is provided with a normally open side exposed outside the second plastic body, and a normally open movable contact is attached to the normally open side of the movable contact spring piece, and the other side of the movable contact spring piece corresponding to the normally open side is completely covered within the second plastic body.

3. A microminiature relay having a large creepage distance according to claim 1 or 2.

4. The horizontal cross section of the first plastic body has a rectangular or nearly rectangular shape, and a first groove is provided on a side wall of the first plastic body corresponding to a long side of the rectangle, on a surface path corresponding to a portion of the coil terminal exposed from the first plastic body and a welding table exposed from the first plastic body, and the first groove is used to increase the surface distance between the portion of the coil terminal exposed from the first plastic body and the welding table.

2. A microminiature relay having a high creepage distance according to claim 1.

5. The horizontal cross section of the first plastic body has a rectangular or nearly rectangular shape, and a first barrier is further provided at a side wall corresponding to a long side of the rectangle of the first plastic body, at a top end adjacent to one end of the first plastic body, protruding upward, so that a creeping path from a portion of the coil terminal exposed from the first plastic body through the iron core to the normally open end contact creeps along the side wall corresponding to the short side of the rectangle of the first plastic body.

2. A microminiature relay having a high creepage distance according to claim 1.

6. A second groove is provided on a side wall corresponding to a short side of the rectangle of the first plastic body in a creepage path corresponding to a portion of the coil terminal exposed from the first plastic body and one end of the iron core, and the second groove is used to increase the creepage distance from the portion of the coil terminal exposed from the first plastic body through the iron core to the normally open end contact.

6. A microminiature relay having a high creepage distance according to claim 5.

7. A second barrier is further provided at an upper end of the first plastic body in a corresponding creepage path between the other end of the core and the normally open end contact, and the second barrier is used to further increase the creepage distance from the portion of the coil terminal exposed from the first plastic body through the core to the normally open end contact.

7. A microminiature relay having a high creepage distance according to claim 6.

8. The combination of the movable contact spring and the armature further includes a permanent magnet, the permanent magnet being distributed along the longitudinal direction of the armature and stacked with the armature, and the permanent magnet being offset toward the other end of the first plastic body.

4. A microminiature relay having a high creepage distance according to claim 3.

9. The fixed contact spring further includes a common end lead terminal that is exposed from the first plastic body and faces downward on the welding table, and the common end lead terminal is offset toward the other end of the first plastic body.

9. A microminiature relay having a high creepage distance according to claim 8.

10. The other side of the two sets of movable contact springs corresponding to the normally open side is further electrically connected by a connection sheet, and the connection sheet is completely covered by the second plastic body, and the connection sheet is integrally connected to the two sets of movable contact spring pieces by an integral molding method, or the connection sheet is a separate part, and both ends of the connection sheet are respectively abutted or welded to the two sets of movable contact spring pieces.

9. A microminiature relay having a high creepage distance according to claim 8.

11. The connecting sheet is adjacent to an end position of the corresponding end of the second plastic body, thereby providing sufficient arrangement space for the permanent magnet.

11. A microminiature relay having a high creepage distance according to claim 10.

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